1. Field of the Invention
The present invention is directed to an ink source regulator for an ink-jet printer that is relatively independent upon the inlet pressure, such that the functionality of the regulator is relatively independent of the inlet pressure of the ink source. More specifically, the present invention is directed to dimensional considerations of the regulator and its associated components, as well as methods of assembling the regulator.
2. Background of the Invention
The flow of fluids through predetermined conduits has been generally been accomplished using a valve and/or a pressure source. More specifically, valves come in various shapes and sizes and include as a subset, check valves. These valves prevent the reversal of fluid flow from the direction the fluid passed by the valve. A limitation of check valves is that the volumetric flow of the fluid past the valve is controlled by the inlet side fluid pressure. If the inlet pressure is greater than the outlet pressure, the valve will open and fluid will pass by the valve; if not, the inlet fluid will be relatively stagnant and the valve will not open.
Inkjet printers must take ink from an ink source and direct the ink to the print head where the ink is selectively deposited onto a substrate to form dots comprising an image discernable by the human eye. Two general types of systems have been developed for providing the pressure source to facilitate movement of the ink from the ink source to the print head. These generally include gravitational flow system and pumping systems. Pumping systems as the title would imply create an artificial pressure differential between the ink source and the print head to pump the fluid from the ink source to the print head. Generally, these pumping systems have many moving parts and need complex flow control system operatively coupled thereto. Gravitational flow avoids many of these moving parts and complex systems.
Gravitational fluid flow is the most common way of delivering ink from an ink reservoir to a print head for eventual deposition onto a substrate, especially when the print head includes a carrier for the ink source. However, this gravitational flow may cause a problem in that excess ink is allowed to enter the print head and accumulate, being thereafter released or deposited onto an unintended substrate or onto one or more components of the inkjet printer. Thus, the issue of selective control of ink flow from a gravitational source has also relied upon the use of valves. As discussed above, a check valve has not unitarily been able to solve the problems of regulating ink flow, at least in part because the inlet pressure varies with atmospheric pressure, and when the valve is submerged, the pressure exerted by the fluid itself.
U.S. Pat. No. 6,422,693, entitled “Ink Interconnect Between Print Cartridge and Carriage”, assigned to Hewlett-Packard Company, describes an internal regulator for a print cartridge that regulates the pressure of the ink chamber within the print cartridge. The regulator design includes a plurality of moving parts having many complex features. Thus, there is a need for a regulator to regulate the flow of ink from an ink source to a print head that includes fewer moving parts, that is relatively easy to manufacture and assemble, and that does not necessitate venting to the atmosphere to properly function.